<p> Name______Class______Date______Skills Practice DATASHEET A FOR IN-TEXT LAB Cellular Respiration</p><p>OBJECTIVES • Demonstrate how carbon dioxide affects bromothymol blue when added to the indicator solution. • Describe the effect of temperature on carbon dioxide production by yeast.</p><p>MATERIALS • safety goggles • disposable gloves • lab apron • plastic cups, clear (4) • room temperature water • bromothymol blue • drinking straw, plastic • warm water • ice water • baker’s yeast • ¼ teaspoon • hand lens • sugar</p><p>Procedure 1. Put on safety goggles, gloves, and a lab apron. Fill a clean plastic cup halfway with room temperature water. Add several drops of bromothymol blue to the water. Swirl to mix the solution. CAUTION: Bromothymol blue is a skin and eye irritant.</p><p>2. Insert a clean straw into the solution. Gently blow a steady stream of air through the straw. Note any changes to the solution’s appearance. CAUTION: Be careful not to accidentally drink the solution while blowing into the straw. ______3. Label three plastic cups “A,” “B” and “C.”</p><p>Original content Copyright © by Holt, Rinehart and Winston. Additions and changes to the original content are the responsibility of the instructor. Holt Biology 1 Photosynthesis and Cellular Respiration Name______Class______Date______Cellular Respiration continued 4. Fill cup A with ice water. Fill cup B with room temperature water. Fill cup C with warm water. Add several drops of bromothymol blue solution to each cup. This will make them all look the same. 5.Add ¼ teaspoon of baker’s yeast to each cup. Swirl the cups. Observe the appearance of the solutions every 30 seconds. After 5 minutes, examine the surface of each solution with a hand lens. (Use stopwatch.com for your timer.) Design a table to record your observations:</p><p>6. Clean up your lab materials according to your teacher’s instruction. Wash your hands before you leave the lab.</p><p>Analyze and Conclude 1. Drawing Conclusions What happened to the indicator (bromothymol blue) as exhaled air bubbled through the solution? What caused this change? ______2. Scientific Methods Evaluating Results Did the yeast produce a similar color change? Explain your answer. ______3. Scientific Methods Evaluating Results Did temperature affect the yeast’s production of carbon dioxide? Explain your answer. ______</p><p>Original content Copyright © by Holt, Rinehart and Winston. Additions and changes to the original content are the responsibility of the instructor. Holt Biology 2 Photosynthesis and Cellular Respiration Name______Class______Date______4. Scientific Methods Summarizing Results What did you observe on the surface of the solutions? ______</p><p>______Cellular Respiration continued 5. Predicting Outcomes Will adding sugar to the yeast solution affect the respiration rate? Make a guess. Then, design an experiment that would test the effects of more and less sugar on yeast metabolism. ______</p><p>Conclusion: (Include possible sources of error; what you learned about respiration; refer to data and observations from the lab.)</p><p>Original content Copyright © by Holt, Rinehart and Winston. Additions and changes to the original content are the responsibility of the instructor. Holt Biology 3 Photosynthesis and Cellular Respiration</p>